Threee-component alkyl aluminum catalysts for olefin polymerization



United States Patent 3,139,590 THREE-COMPONENT ALKYL ALUMINUM CATA-LYSTS FOR OLEFIN PGLYMERIZATION Harry W. Coover, In, and Frederick B.Joyner, Kingsport,

Tenn, assignors to Eastman Kodak Company, Rochester, N.Y., a corporationof New Jersey No Drawing. Filed Mar. 1, 1961, Ser. No. 92,482 Theportion of the term of the patent subsequent to September 1, 1981, hasbeen disclaimer! and dedicated to the Public 13 Claims. (Cl. 260-935)This application is a continuation-in-part of our copending application,Serial No. 724,907, filed March 31, 1958, and now abandoned.

This invention relates to a new and improved polymerization process andis particularly concerned with the use of a novel catalyst combinationfor preparing high molecular weight solid polyolefins, such aspolypropylene,

f high density and crystallinity. In a particular aspect the inventionis concerned with the preparation of polypropylene and higherpolyolefins having a high crystallinity and a high density using aparticular catalyst combination which has unexpected catalytic activity.

Polyethylene has heretofore been prepared by high pressure processes togive relatively flexible polymers having a rather high degree of chainbranching and a density considerably lower than the theoretical density.Thus, pressures of the order of 500 atmospheres or more and usually ofthe order of 1000-1500 atmospheres are commonly employed. It has beenfound that more dense polyethylenes can be produced by certain catalystcombinations to give polymers which have very little chain branching anda high degree of crystallinity. The exact reason why certain catalystcombinations give these highly dense and highly crystalline polymers isnot readily understood. Furthermore, the activity of the catalystsordinarily depends upon certain specific catalyst combinations, and theresults are ordinarily highly unpredictable, since relatively minorchanges in the catalyst combination often lead to liquid polymers ratherthan the desired solid polymers.

Catalyst compositions containing metal alkyls and transition metalcompounds have been found to be effective for polymerizing olefins inlow temperature, low pressure procedures and among the most effectivecatalysts are the mixtures of a trialkyl aluminum and either titaniumtrichloride or vanadium trichloride. When these catalysts are employedto polymerize propylene, the product has been found to have an inherentvis cosity within the range of about 1 to 3 and a crystallinity of about70 to 75%. Also, such polymers have inadequate stiffness, thermalstability and softening point for many commercial applications unlessstabilized and sub jected to rather extensive extraction procedures forremoval of oily and rubbery polymers.

It is an object of this invention to provide a novel and improvedprocess for polymerizing propylene and higher a-monoolefins to formpolymers of increased inherent viscosity and molecular weight and ofsubstantially higher crystallinity. It is a particular object of thisinvention to provide a novel and improved process for polymerizingpropylene in the presence of an improved catalyst composition containinga trialkyl aluminum and either titanium trichloride or vanadiumtrichloride. As a result of the use of this improved catalystcomposition the inherent viscosity and crystallinity of the polymer areunexpectedly improved resulting in a polymer of i substantiallyincreased molecular weight and impact strength and in substantiallyincreased clarity of molded objects. Other objects of this inventionwill be apparent from the description and claims which follow.

Bldhfihfi Patented June 15, 1965 The above and other objects areattained by means of this invention, wherein u-monoolefins, eithersingly or in admixture, are readily polymerized to high molecular weightsolid polymers by eliecting the polymerization in the presence of acatalytic mixture containing an aluminum compound having the formulaR3A1 wherein each R is a hydrocarbon radical containing 1 to 12 carbonatoms and selected from the group consisting of alkyl, aryl and aralkyl,a halide of a transition metal selected from the group consisting oftitanium and vanadium, and an amide as a third component. The amide canhave the structural formula wherein R is a radical selected from thegroup consisting of hydrogen, alkyl radicals containing from 1 to 20carbon atoms, phenyl, carboxyl, alkoxy, -N(R) wherein R is an alkylradical containing 1 to 4 carbon atoms, and

(CH) 2 n wherein n is an integer of l to 4, and each of R and R is aradical selected from the group consisting of hydrogen, alkyl radicalscontaining 1 to 8 carbon atoms, phenyl and cyclohexyl.

The amide third component of the catalyst can have the structuralformula wherein n is an integer of l to 4 and R is a radical selectedfrom the group consisting of alkyl radicals containing 1 to 4 carbonatoms and phenyl.

Amide third components that can be used in the catalyst system areN,N-dimethylformamide, N,N-dimethylacetamide, N,N-diethylacetamide,N-cyclohexylacetamide, N-t-butylbenzamide, N-methyl N phenylacetamide, Nbenzylacetamide, n-heptamide, palmitamide, stearanillde, acetanilide,isobutyramide, N,N-di-t-butylurea, tetramethylurea, succinimide,N,N,N,N'-tetramethyladipamide, N- methylisobutyramide, Nbenzoylmorpholine, N,N' diacetylpiperazine, n-butyloxamate,ethyloxanilate and ethyl carbamate.

Catalyst mixtures that can be employed in practicing our invention are:

(a) Triethyl aluminum, titanium trichloride and N- cyclohexylacetamide;

(b) Tributyl aluminum, titanium tetrachloride and N-methyl-N-phenylacetamide;

(c) Trioctyl aluminum, vanadium trichloride and palmitamide;

(d) Tridodecyl aluminum, vanadium tetrachloride and acetanllide;

(e) Triphenyl aluminum, vanadium bromide and isobutyrarnide;

(f) Tribenzyl aluminum, titanium trioromide and N, N-di-t-butylurea;

(g) Trinaphthyl aluminum, titanium tetraiodide and ethyl caroamate; and

(h) Tripropyl aluminum, titanium triiodide and nheptamide.

The significantly improved properties of the polymers '3 produced'withthe above catalyst were completely unexpected. The inventive process iscarried out in liquid phase in an inert organic liquid and preferably aninert 7 liquid hydrocarbon vehicle, but the reaction can be conducted inthe absence of diluent. The process proceeds with excellent results overa temperature range of from C. to 250 C. although it" is preferred tooperate within the range of from about 50 C. to about 150 C. Likewise,the reaction pressures may be varied widely from about. atmosphericpressure to very high pressures of the order of 20,000 p.s.i. or higher.A particular advantage of the invention is that pressures ofthe order of30 to 1000 p.s.i. give excellent results, and it is not neces: sary toemploy theextremely high pressures which 'were necessary heretofore.Thelliquid vehicle employed is desirably one which serves as an inertliquid reaction medium. 7 a a The invention is of particular importancein the preparation of highly crystalline polypropylene although it canbe used for polymerizing mixtures of ethylene and propylene, the butenesand styrene as well as other a-monoolefins containing up to 10 carbonatoms. The polypropylene produced in accordance with this inventionpossesses properties that arequite unexpected. The inherent viscosityand crystallinity. of the polymer as well as the molecular weight,impact strength and clarity are substantially and unexpectedlyimproved.The high molecular Weight, high density polymers of this invention areinsoluble in solvents at ordinary temperatures but are partially solublein such solvents as xylene, toluene or tetralin at elevatedtemperatures. These solubility characteristics make it possible to carryout the polymerization process under conditions wherein the polymerformed is V polymerization progresses. V

The polymerization embodying the inventioncan be 4 7 ally, it is notdesirable or economical to effect the polym erization at temperaturesbelow 0 C., and the process can be readily controlled at roomtemperature or higher which is an advantage from thestandpoint of commercial processing. The pressure employed is usually only I sur'hcient tomaintain the reaction mixture in liquid form during the polymerization,although higher pressures can be used if desired. The pressure isordinarily achieved by pressuring the system With the monomer wherebyadditional monomer dissolves in the reaction vehicle as the This resultsin formation oi polymer or" extremely uniform molecular weightdistribution over a relatively narrow range' Such uniform polymerspossess distinct advanvalue within the preferred range in order toachieve the solublein the reaction medium during the polymerization andcan be' precipitated therefrom by lowering. the temperature of theresulting mixture. The polypropylene produced by'practicing thisinvention has a softening point above 155. C. and a density of 0.91 andhigher. Usually, the density of the polypropylene is of the order of0.91 to 0.92. r

The polypropylene and other polyolefins prepared in accordance with theinvention can be molded or extruded and can be used to form plates,sheets, films, or a variety of molded objects which exhibit a higherdegree of stiffness than do the corresponding high pressure polyolefins.The products can be'extruded in the form of pipe or tubing of excellentrigidity and can be injection molded into a great variety of articles.The polymers can 7 also be cold drawn into ribbons, bands, fibers orfilaments of high elasticity and rigidity. Fibers of high strength canbe spun from the molten polypropylene obtained according to thisprocess. Other poly-a-o lefins as well as .copolymers of ethylene andpropylene can also be pre- .pared and have similarly improvedproperties.

As has been indicated above, the improved results 0 obtained inaccordance with this invention depend upon the particular catalystcombination. Thus, one of the components of the catalyst is an aluminumcompound as gen is selected from the group con'sisting'of chlorine,bromine and iodine. The third component of the catalyst composition isan amide as defined above.

The'limiting factor ,in'the temperature of the process appears to be thedecomposition temperature of the catalyst.

are employed, although temperatures as low at 0 C.

or as high as 250 C. can be employed if desired. Usu- Ordinarily,temperatures from 50 C. tolSO" C.

tages since they do not contain any substantial amount 7 of the lowmolecular weight or'high molecular weight formations which areordinarily found in polymers prepared by batch reactions. 7 V v In thecontinuous flowing stream process, the temperature is desirablymaintained at a substantially constant highest degree of uniformity.Since it is desirable to employ a solution of the monomer of relativelyhigh concentration, the process is desirably efiected under a pressureof from 30 to 1000 psi. obtained by pressuring the system with themonomer being polymerized. The amount of vehicle employed can be variedover rather Wide. limits with relation to the monomer and catalystmixture. Best results are obtained using a concentration of catalyst offrom about 0.1% to about 2% by weight based on the weight of thevehicle. The concentration of the monomer in the vehicle will varyrather widely depending upon the reaction conditions and will usuallyrange from about 2 to 50% by weight. For a solution type of process itis preferred to use a concentration from about 2 to about 10% by weightbased on the weight of the vehicle, and for a slurry type of processhigher concentrations, for example up to 40% and higher, are preterred.Higher concentrations of monomer ordinarily increase the rate ofpolymerization, but concentrations above 5 to 10% by weight in asolution process are ordinarily less desirable because the polymerdissolved in the reaction medium results. in a very viscous solution.

The molar ratio of aluminum compound totransition 'met al trihalide canbe varied within the range of 1:0.5

the third component per mole of aluminum compound. The polymerizationtime can be varied as desired and will usually be of'the order of from30 minutes to several hours in batch processes; Contact times of from 1to .4

in the polymerization zone can also be regulated as desiredyand in somecases it is not necessary toemploy reaction or contact times much beyondone-half to one hour since a cyclic system can be employed byprecipitation of the polymer and return of the vehicle and unusedreplenished and additional monomer introduced.

The organic vehicle employed can be an aliphatic alkane or cycloalkanesuch as pentane, hexane, hept-ane or cyclohexane, or a hydrogenatedaromatic compound such as tetrahydronaphthalene or decahydronaphthalene,or a high molecular weight liquid parafiin or mixture of paraffins whichare liquid at the reaction temperature, or an aromatic hydrocarbon suchas benzene, toluene, xylene, or the like, or a halogenated aromaticcompound such as chlorobenzene, chloronaphthalene, ororthodichlorobenzene. The nature of the vehicle is subject toconsiderable variation, although the vehicle employed should be liquidunder the conditions of reaction and relatively inert. The hydrocarbonliquids are desirably employed. Other solvents which can be used includeethyl benzene, isopropyl benzene, ethyl toluene, n-propyl benzene,-diethyl benzenes, mono and dialkyl naphthalenes, n-pentane, n-octane,isooctane, methyl cyclohexane, tetralin, decalin, and any of the otherwell known inert liquid hydrocarbons.

The polymerization ordinarily is accomplished by merely admixing thecomponents of the polymerization mixture, and no additional heat isnecessary unless it is desired to efiect the polymerization at anelevated temperature in order to increase the solubility of polymericproduct in the vehicle. When the highly uniform polymers are desiredemploying the continuous process wherein the relative proportions of thevarious components are maintained substantially constant, thetemperature is desirably controlled within a relatively narrow range.This is readily accomplished since the solvent vehicle forms a highpercentage of the polymerization mixture and hence can be heated orcooled to maintain the temperature as desired.

A particularly effective catalyst for polymerizing propylene and othera-monoolefins in accordance with this invention is a mixture of triethylaluminum, titanium trichloride and N,N-dimethyl formamide. Theimportance of the third component of this reaction mixture is evidentfrom the fact that the presence of the third component makes possiblethe production of polymers of substantially improved properties.

The invent-ion is illustrated by the following examples of certainpreferred embodiments thereof.

Example 1 In a nitrogen-filled dry box, a total of 2 g. of catalyst wasadded to a 500-ml. pressure bottle containing 100 ml. of dry heptane.The catalyst was made up of triethylaluminum, titanium tetrachloride andN,N-dimethylformamide in a molar ratio of 2:2: 1. The pressure bottlewas then attached to a source of propylene, and the reaction mixture wasagitated, heated to 75 C. and maintained under 30 psi. propylenepressure for 6 hours. At the end of this time, the bottle was removedfrom the propylene source, dry iscbutyl alcohol was added to deactivatethe catalyst, and then the polymer was washed with hot, dry isobutanolto remove the catalyst residues. The yield of highly crystallinepolypropylene was 14.2 g. This polymer had an inherent viscosity intetralin at 145 C. of 2.10 and a density of 0.908. When a control runwas made using only the triethylaluminum and titanium tetrachloride andomitting the N,N-dimethylformam-ide, very little crystallinepolypropylene was formed under these conditions.

Example 2 Inside a nitrogen-filled dry box, a 285-ml. stainless steelautoclave was loaded with 2 g. of three-component catalyst comprising a1:l:0.25 molar ratio of triethylaluminum, titanium trichloride andN,N-dimethylacetamide and 100 ml. of dry mineral spirits (BE. 197 C.).The autoclave was sealed, placed in a rocker, and 100 ml. (51 g.) ofdry, liquid propylene was added. Rocking was initiated, and the mixturewas heated to 85 C. and maintained at this temperature for 6 hours. Thepolymer was worked up as described in Example 1 to give a yield of 40 g.of highly crystalline polypropylene having an inherent viscosity of 2.55in tetralin at 145 C. 'When hydrogen was admitted to the polymerizationvessel and was maintained there at 50 p.s.i. partial pressure, theinherent viscosity of the product was 1.90. An increase in the hydrogenpressure to 500 p.s.i. in a similar experiment produced a very lowmolecular weight crystalline polypropylene of inherent viscosity 0.40.

Example 3 The procedure of Example 2 was used to polymerize propylenewith no solvent present. One hundred grams of liquid propylene monomerwas used and within the 6-hour reaction period at C., a 98.5-g. yield ofhighly crystalline polypropylene of inherent viscosity 3.45 wasobtained.

Example 4 The procedure of Example 2 was employed to polymerize a 50-g.charge of 3-methyl-1-ibutene using 3 g. of catalyst made up oftriethylaluminum, vanadium trichloride and tetramethylurea in a molarratio of 121:0.1. The yield was 43.7 g. of highly crystallinepoly(3-methyll-butene). This polymer in the form of an oriented fibergave a crystalline melting point of 308 to 310 C.

Example 5 The procedure of Example 2 was used to polymerize a SO-g.charge of styrene using 0.75 g. of catalyst comprised oftriethyl-aluminum, vanadium trichloride and N- benzoylmol'pholine. A45-g. yield of crystalline polystyrene was obtained. This polymer had aninherent viscosity of 2.6 8 and a crystalline melting point (powder) of231-238 C.

Example 6 In a nitrogen-filled dry box, a 7-oz. tapered pressure bottlewas charged in order with 40 ml. of dry benzene, 20 g. of4-methyl-l-pentene and 1 g. of a catalyst consisting oftriethyl-aluminum, vanadium tetrachloride and N,N-diacetylpiperazine ina molar ratio of 1:3:1. The bottle was capped, placed in aconstant-temperature water bath maintained at 70 C. and was allowed toremain under these conditions :for 24 hours. At the end of this period,the bottle was removed, allowed to cool and opened. The polymer wasdissolved in hot xylene and reprecipitated by the addition of dryisobutanol to the xylene solution in a \Varing Blend-or. The polymer waswashed several times with hot isobutanol and was dried. The crystallinepoly(4-methyl-1-pentene) weighed l 7.2 g. and melted at 200 to 205 C.(powder).

Allylbenzene, vinylcyclohexane, butadiene, isoprene, and3-phcnyl-l-butene were readily polymerized by this procedure to givesolid polymers.

Other amides which gave similar results when used in place ofN,N'-diacetylpiperazine include N,N,N,N- tetramethyladipamide,tetramethy-lurea, ethyl oxanilate and palmitamide.

Example 7 The procedure of Example 2 was followed except that thecatalyst charge was 1 g. of a mixture of triethylaluminum, titaniumt-richl'oride and N,N-diethylacetamide in a molar ratio of 1:l:0.5. Nosolvent was employed and the polymerization temperature was 85 C. Thecrystalline polypropylene obtained had a density of 0.913

' and an inherent viscosity of 2.40.

Other amides which may be used in place of N,N- diethylacetamide to givesimilar results include N-benzylacetamide, succinimide,N-methylisobutyramide and nbutyl oxamate.

The diluents that are employed in practicing this invention can beadvantageously purified prior to use in the polymerization reaction bycont-acting the diluent, for example in a distillation procedure orotherwise, with the polymerization catalyst to remove undesirableimpurities. Also, prior to such purification of the diluent the catalystdrocarbons.

can be contacted advantageously with polymerizable ix- 7 monoolefins.

Thus, by'means of this invention polyolefins such as poly-propylene arereadily produced using a catalyst com bination whose improvedeffectiveness could not have been predicted. The polymers thusobtainedcan be ex- From the detailed disclosure of this invention it isquite' apparent that in this polymerizationprocedure a novel'catalyst,not suggested in prior art polymerization procedures, is employed' As aresult of the use of this novel catalyst it is possible to producepolymeric hydrocarbons, particularly polypropylene, having propertiesnot heretofore obtainable. For example, polypropylene preparedin thepresence, of catalyst combinations within the scope of this invention issubstantially free of rubbery and oily polymers and thus it is notnecessary to subject such polypropylene of this invention to extractionprocedures in order to obtain a commercial product. Also, polypropyleneproduced in accordance with this invention possesses unexpectedly high.crystallinity, an unusually high softening point and outstanding thermalstability. Such polypropylene also has a very high stiffness as a resultof the unexpectedly high crystallinity. The properties imparted to.polypropylene prepared in accordance with this invention thuscharacterize and distinguish this polypropylene from polymers preparedby prior art polymerization procedures. 7 I

The novel catalysts defined above can'be used to produce high molecularweight crystalline polymeric hy- The molecular Weight of the polymerscan be varied over a. wide range by introducing hydrogen to thepolymerization reaction. Such hydrogen can be introduced separately orin admixture with the olefin monomer. The polymers producedin'accordance. with this invent-ion can be separated from polymerizationcat- Although the invention has been described in consider-.

able detail with reference to certain preferred embodiments thereof,variations and modifications can be effected within the spirit and scopeof this invention as described above and as defined in the appendedclaims.

'We claim: 7

1. In the polymerization of alphamonoolefinic hydro carbon material toform solid crystalline polymer, theimprovement which comprisescatalyzing the polymeriza tion with a catalytic mixture containing analuminum compound having the formula R Al whereinR is a hydrocarbonradical containing 1 to 12 carbon atoms selected from the groupconsisting of alkyl, aryl and aralkyl, a

halide of atransition'metal selected from the group consistingoftitanium and vanadium, and a third component selected from the amideshaving the formulas: 1

and i r a o i ll NC-R4 2) n 2) n .N%R4

o a .wherein R is a radicalselected from the group consisting of alkylradicals containing 1 to 20 carbon atoms, phenyl, carboxyl, alkoxy,-N(R) wherein R is an alkyl radical containing l to 4 carbon atoms and TV V o 2R3 i cH2 '..,bN 7 7 V 7 R3 V V wherein n is an integer of 1 to 4and each or R and R is a radical selected from the group consisting ofhydrogen, alkyl radicals containing 1 to 8 carbon atoms,

phenyl and cyclohexyl, and wherein R is a radical se-' 'lected from thegroup consisting of alliyl radicals contain ing 1" to 4 carbon atoms andphenyl aud t is an integer 2. In the polymerization-of atleast onemonoolefin'from the group consisting of ethylene and propylene to formsolid'crystalline polymer, the improvement which com-' prises effectingthe polymerization in the presence of a catalytic mixture of a tri-loweralkyl aluminum, a titanium radical containing 1 to 4 carbon atoms and R37 V g wherein n is an integer of 1 to 4 and each ofR and R is a radicalselected from the group consisting ofhydrogen, alkyl radicals containing1 to 8 carbon atoms, phenyl and cyclohexyl. i f

3. In the polymerization "of at least one monoolefin from the groupconsisting of ethylene and propylene to form solid crystalline polymer,the improvement which mcoprises etfectin the polymerization'in thepresence of a catalytic mixture of a tri-lower alhyl aluminum, a

titanium halide and a third component selected from the.

amides having the formula V /NCR4 (man o w en wherein R is a radicalselected fromthe group consisting of alkyl radicals containing 1 to 4carbon atoms and phenyl and n is an integer of 1 to 4.

7 4. In the 'polymeriz ation'of at least one mon o olefin' 'from thegroup consisting of ethylene and propylene to form solid crystallinepolymer, the improvement which comprises eifecting the polymerization inthe presence of a catalytic mixture of a tri-lower alkyl aluminum, atitanium halide and a third component selected from the amides havingthe formula:

on on wherein R is a radical selected from the group consisting of alkylradicals containing 1 to 4 carbon atoms and phenyl and n is an integerof 1 to 4.

5. In the polymerization of propylene to form solid crystalline polymer,the improvement which comprises efiecting the polymerization in thepresence of a catalytic mixture of triethyl aluminum, titaniumtrichloride and N,N-dimethylformamide.

6. The method according to claim 5 wherein vanadium trichloride is usedin the catalyst mixture in place of titanium trichloride.

7. The method according to claim 5 wherein N,N-dimethylacetamide is usedin the catalyst mixture in place of N,N-dimethylformamide.

8. In the polymerization of propylene to form solid crystalline polymer,the improvement which comprises effecting the polymerization in thepresence of a catalytic mixture of triethyl aluminum, titaniumtetrachloride and N,N,N', -tetramethyladipamide.

9. In the polymerization of propylene to form solid crystalline polymer,the improvement which comprises efiecting the polymerization in thepresence of a catalytic mixture of tripropyl aluminum, titaniumtetrachloride and n-heptarnide.

10. As a composition of matter, a catalytic mixture containing analuminum compound having the formula R Al wherein R is a hydrocarbonradical containing 1 to 12 carbon atoms selected from the groupconsisting of alkyl, aryl and aralkyl, a halide of a transition metalselected from the group consisting of titanium and vanadium, and a thirdcomponent selected from the amides having the formulas:

wherein R is a radical selected from the group consisting of alkylradicals containing 1 to 20 carbon atoms, phenyl, carboxyl, alkoxy,-N(R) wherein R is an alkyl radical containing 1 to 4 carbon atoms and n(CH )n,oN

s wherein n is an integer of l to 4 and each of R and R is a radicalselected from the group consisting of hydrogen, alkyl radicalscontaining 1 to 8 carbon atoms, phenyl and cyclohexyl, and wherein R isa radical selected from the group consisting of alkyl radicalscontaining 1 to 4 carbon atoms and phenyl and n is an integer of 1 to 4.11. As a composition of matter, a catalytic mixture of a tri-lower alkylaluminum, a titanium halide and a third component selected from theamides having the formula:

R1CN

wherein R is a radical selected from the group consisting of alkylradicals containing 1 to 20 carbon atoms, phenyl, carboxyl, alkoxy, N(R)wherein R is an alkyl radical containing 1 to 4 carbon atoms and whereinn, is an integer of 1 to 4 and each of R and R is a radical selectedfrom the group consisting of hydrogen, alkyl radicals containing 1 to 8carbon atoms, phenyl and cyclohexyl.

12. As a composition of matter, a catalytic mixture of a tri-lower alkylaluminum, a titanium halide and a third component selected from theamides having the formula:

wherein R is a radical selected from the group consisting of alkylradicals containing 1 to 4 carbon atoms and phenyl and n is an integerof 1 to 4.

13. As a composition of matter, a catalytic mixture of a tri-lower alkylaluminum, a titanium halide and a third component selected from theamides having the formula:

wherein R is a radical selected from the group consisting of alkylradicals containing 1 to 4 carbon atoms and phenyl and n is an integerof 1 to 4.

14. As a composition of matter, a catalytic mixture of triethylaluminum, titanium trichloride and N,N-dimethylformamide.

15. A composition according to claim 14 wherein vanadium trichloride isused in the catalyst mixture in place of titanium trichloride.

16. A composition according to claim 14 wherein N,N- dimethylacetamideis used in the catalyst mixture in place of N,N-dimethylformamide.

17. As a composition of matter, a catalytic mixture of triethylaluminum, titanium tetrachloride and N,N,N',N'- tetramethyladipamide.

18. As a composition of matter, a catalytic mixture of tripropylaluminum, titanium tetrachloride and n-heptamide.

References Cited by the Examiner UNITED STATES PATENTS 2,886,561 5/59Reynolds et al 260--94.9 2,969,345 1/61 Coover et al. 260-93] 2,973,3482/61 Coover et a1. 26093.7 3,004,020 10/61 Young et al 260-943 FOREIGNPATENTS 837,164 6/60 Great Britain.

JOSEPH L. SCHOFER, Primary Examiner.

M. LIEBMAN WILLIAM H. SHORT, Examiners.

1. IN THE POLYMERIZTION OF ALPHA-MONOOLEFINIC HYDROCARBON MATERIAL TOFORM SOLID CRYSTALLINE POLYMER, THE IMPROVEMENT WHICH COMPRISESCATALYZING THE POLYMERIZATION WITH A CATALYTIC MIXTURE CONTAINING ANALUMINUM COMPOUND HAVING THE FORMULA R3 AL WHEREIN R IS A HYDROCARBONRADICAL CONTAINING 1 TO 12 CARBON ATOMS SELECTED FROM THE GROUPCONSISTING OF ALKYL, ARYL AND ARALKYL, A HALIDE OF A TRANSITION METALSELECTED FROM THE GROUP CON SISTING OF TITANIUM AND VANADIUM, AND ATHIRD COMPONENT SELECTED FROM THE AMINDES HAVING THE FORMULAS: